Yellow skin on the bottoms of the feet is usually caused by a buildup of pigment or thickened skin in that area, rather than a serious illness. The most common reasons are carotene buildup from diet or changes in the outer layer of the skin, which can look yellow on soles because the skin there is thicker.
The color is often more noticeable on palms and soles because these areas have a thick outer skin layer and many sweat glands. Conditions like palmoplantar keratoderma cause the skin to become thick, hard, and yellowish over time. In some people, diabetes or changes in fat metabolism can also lead to yellow discoloration that shows up mainly on the feet, even when the eyes stay white.
Timing and spread matter. If the yellow color has been there for months, is limited to pressure areas like heels, and is not spreading elsewhere, it is more likely related to skin thickening or pigment buildup. Yellow skin along with yellow eyes, dark urine, or fatigue is different and needs urgent medical care.
Avoid scrubbing aggressively or using medicated creams on your own. A primary care doctor or dermatologist can check the skin and decide if blood tests or simple skin care is needed.